• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.4
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• pp.67-75
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• 2000

A simulation model for reservoir sizing was developed to be applied in a region with insufficient hydrological data. Reservoir storage balance equation was formulated on a monthly basis. Gajiyama equation was generalized to estimate monthly reservoir inflow more accurately. Monthly evaporation equation on a reservoir water surface was introduced , which was functioned with monthly mean temperature. Generalized Gajiyama equation was applied to estmate reservoir inflow of the Sayeon dam. Nash-Sutcliffe's model efficiency was 0.793. Using developed model for reservoir sizing, water supply capacity was analyzed with 118.000㎥/day on the Sayeon dam. This showed a reasonable result as compared with 110000㎥/day in other technical report. For general application of developed model, a virtual reservoir was considered and its dta of surface area and volume by elevation was prepared using DEM. Using the model, size of reservoir was determined and water supply capacity was anlayzed on a virtual reservoir.

• ALGAE
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• v.19 no.1
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• pp.23-30
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• 2004

The purpose of this study is to assess the effects that hydraulic-gun-aerators have on cyanobactedial bloom in Sayeon Dam Reservoir in Ulsan City, Korea. A total of nine hydraulic-gun-aerators are in operation at the reservoir withe 100 m spacing between each aerator to control severe cyanobacterial bloom in the dam reservoir. The field studies were performed an total four times at two sampling stations in the reservoir from July to August in 2001. The standing crops of phytoplankton did not changed significantly by the operation. The cell concentration of the cyanobacteria at the surface layer were reduced about 10%, which is a poor result for the dispersing cyandobacteria deeper into the water. The average surface temperature during the study was reduced by 2.0$^{\circ}C$ by the hydraulic-gun-aerators. The effect of the operation on the vertical distribution of DO concentration was clear. However, the hydraulic-gun-aerators were not expected to have an effect in the lowest layer of the hypolimnion. In the study, it was proposed that installation distance between each hydraulic-gun-aerator would be proper when they are apart about 120 m based on DO depth profiles.

• Journal of Korea Water Resources Association
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• v.46 no.12
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• pp.1157-1167
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• 2013

Sayeon dam is the one that is structured in 1965 and supplying residential water in Ulsan. The hill located within the reservoir near the entrance of the dam spillway plays a role as a natural Dike. According to the recent surveys on change of sediment and effective volume of water kept in store, the latter that decreased 2.92% from twenty million tons and the former increased just 1.65 m. In this survey we examined the application of SED-2D model using measured data of Sayeon dam sediment. In addition we surveyed the inflow control and the water depth to be kept when installing small hydraulic structure similar to Dike around the dam reservoir entrance. To do this, we simulated the hydraulic effects and sediment on the conditions eliminating the hill or installing the structure higher than it. The controlling effects of present hill or adding small hydraulic structure on it was found, though the changes of the measure was not large.